This could be a memory 'spill-over' event where then I/O is utilized to complete the transaction.
In the advanced OLAP server settings in SAS Management Console, you could tweek a couple of the settings:
Performance - Number of Threads to Spawn - should equal the # of CPUs
Query Thread Pool - Minimum Number = 1
- Maximum Number = 2*# available CPUs
Memory size for subquery cache - modify this upwards to increase amt memory used before going to I/O - HOWEVER monitor this closely since it could negatively affect memory available for other types of processing.
~Angela Hall
http://sas-bi.blogspot.com